Portable lamp



FIG. 1 is a front and bottom perspective view of a portable lamp showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is top plan view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a left side elevational view thereof; and,

FIG. 7 is a rear elevational view thereof.

The broken line showing is included for the purpose of illustrating only and forms no part of the claimed design. 

The ornamental design for a portable lamp, as shown and described. 